Aase syndrome is a rare disorder that involves anemia and certain joint and skeletal deformities.
Aase-Smith syndrome; Hypoplastic anemia - triphalangeal thumbs, Aase-Smith type; Diamond-Blackfan with AS-II
Many cases of Aase syndrome occur without a known reason and are not passed down through families (inherited). However, some cases (45%) have been shown to be inherited. These are due to a change in 1 of 20 genes important for making protein correctly (the genes make ribosomal proteins).
This condition is similar to Diamond-Blackfan anemia, and the two conditions should not be separated. A missing piece on chromosome 19 is found in some people with Diamond-Blackfan anemia.
The anemia in Aase syndrome is caused by poor development of the bone marrow, which is where blood cells are formed.
Symptoms may include:
- Absent or small knuckles
- Cleft palate
- Deformed ears
- Droopy eyelids
- Inability to fully extend the joints from birth
- Narrow shoulders
- Pale skin
- Triple-jointed thumbs
Exams and Tests
The health care provider will perform a physical exam. Tests that may be done include:
Treatment may involve blood transfusions in the first year of life to treat anemia.
A steroid medicine called prednisone has also been used to treat anemia associated with Aase syndrome. However, it should only be used after reviewing the benefits and risks with a provider who has experience treating anemias.
A bone marrow transplant may be necessary if other treatment fails.
The anemia tends to improve with age.
Complications related to anemia include:
- Decreased oxygen in the blood
Heart problems can lead to a variety of complications, depending on the specific defect.
Severe cases of Aase syndrome have been associated with stillbirth or early death.
Genetic counseling is recommended if you have a family history of this syndrome and wish to become pregnant.
Clinton C, Gazda HT. Diamond-Blackfan anemia. GeneReviews. 2014:9. PMID: 20301769 www.ncbi.nlm.nih.gov/pubmed/20301769. Updated March 7, 2019. Accessed July 31, 2019.
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Thornburg CD. Congenital hypoplastic anemia (Diamond-Blackfan anemia). In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 475.